A wide variety of failures can result in loss of data, and recoveries of those files become an imperative task to let any enterprise continue functioning. File recovery is the salvaging process, where the lost data in files, failed, wrecked or inaccessible storages, mainly primary storages, such as the disk system, and different other storage media, are retrieved through special software. The situation generally arises out of physical damage to the storage device or in the event of any logical failures in the file system, which makes these media normally inaccessible. There is ofcourse that misconception that file recovery may also pertain to recovery of data which have been deleted.



Storage media, such as, CDs, Tapes, hard disks, etc., can go through many types of physical damage, which causes data or file damages. There could be partial or complete data losses. This may be due to many factors of physical damage and mechanical failures, with crashing of the head of a disk and failed motors, tapes which simply breaks away, etc. In such mechanical damages, there is bound to be some data or file losses and in lots of cases the logical structures of the files may be damaged as well.

The usual physical damage that occurs in our system cannot be rectified by the end users. Taking out a disk system from a computer need an expert handling, as otherwise dust settling of the surface can inevitably damage the platters, resulting in complications in the recovery process. In most of the cases, users do not have the technical expertise required to handle hardware failures and therefore, such specialists are required to handle the situation more than often. In order to do such repairs, you will need to have specified environmental conditions, viz., use Class 100 clean room facilities, in order to protect your hardware sub-assemblies from environmental damage, while repairs are being carried out. Such repairs would perhaps require a kind of data or file recovery software, where, generally the raw image is extracted from the storage media, transforming it to usable data using reconstruction process. This is done after successful repair of the physical damage of the concerned storage media.

The most known logical damage of a storage system occurs from power fluctuations or outages, where the file system structure is not completely written in the storage medium. In the same manner, especially the failures of controller system, such as RAID (Redundant Arrays of Inexpensive Disks) controllers contribute to such grave failures. Logical failures leave the files in an inconsistent state, causing various kinds of problems, for example, infinitely re-cursing directories, drives reporting negative amounts of free space, system crashes with actual loss of data, etc. In modern operating systems, there is some sort of software tool to enable repair these sorts of failures, by correcting the inconsistencies in their native file systems. With Linux we find the fsck utility, Mac OS X has a disk utility and Windows provides the de-fragmentation and chkdsk facilities. Though the de-fragmentation found in today's Windows operating systems, such as, Windows XP Professional are much like the one offered by Norton, it appears that Norton has a more comprehensive software for de-fragmentation process. There are ofcourse third party utilities available, such as, The Coroners Toolkit and The Sleuth. Internet search also reveals free download of such utilities, claiming to be the ones which can take care of file recovery procedures.

There are file recovery software which would recover lost and deleted files, which may have been lost due to corruption in a mass storage media, may be due to loss in format or other means, like, virus, or trojan infection. These may lead to system shut down and total software failure. These utilities may be termed as 'self service file recovery system', and may be considered to be an alternative to the deployment of professional data recovery services, if such failures are not too grave. Most of the software work on disk image creation, creating image files applying different compression method. Other do-it-yourself software vendors claim that as long as the hardware is operational, any failed file system can be recovered, even recovering data lost due to failed RAID system.

There are free downloads of such data or file recovery software available from the internet sources. These tools have quite substantial features in recovering your lost data, so long as the hardware has not been physically damaged, as for example the physical damages of prime storage systems, as discussed in the earlier part of this article. If that is the case, you still have a chance to recover your lost data with these free or inexpensive data recovery software utilities. Free data recovery utilities are seldom available, which really do the job as they claim, and before installing these free software tools, reviews, if available, should ideally be looked into.

There are two important aspects to be considered with data or file recovery. If your data is valuable and used in mission critical applications, you should not be concerned with freeware. If you should try one, try the ones which do not require installation in your computer system. But it is recommended that in cases of failures in critical environments, you should seek the help of data recovery service agents, who are professionally equipped and experienced in such disaster recovery scenario. If you should decide to go in for freeware or shareware applications try to use the ones which do not require installation. Instead the software should run out of a CD, a Flash Drive or a second drive that you might have. If not, you may face a situation where all your data could get permanently over-written.